This invention relates to computer systems with a processor which communicates with I/O devices via an I/O bus, and to a monitor unit and method for such systems.
In such a system, bus cycles to I/O devices usually end with successful data transfer. If something goes wrong, the I/O cycles can end with a data exception. Data exception handling is a well known and accepted technique in computer system design. However, there are times when it is inconvenient or impossible to handle such a data exception in the software being executed in the processor.
An aim of the invention is to seek to avoid the need for data exception handling by the processor software.